CITESwoodID: descriptions, illustrations, identification, and information retrieval

DELTA Home

H. G. Richter, K. Gembruch, G. Koch

Character list and notes

Nomenclature etc.

#1. Family:/

— Following international convention the database features the full taxonomic information on all included taxa, i.e. family, genus and, when applicable, species and authority. Current information on taxonomic nomenclature has been extracted from textbooks such as the latest addition of the "Plantbook" (Mabberly 2008) and internet web pages, among others the USDA Germplasm Resources Information Network (http://www.ars-grin.gov/cgi-bin/npgs/html/taxgenform.pl).

#2. Other trade relevant species:/

— In cases where CITES protection extends to entire genera, e.g., "lignum vitae" (Guaiacum spp.) or "ramin" (Gonystylus spp.), or local groups of genera, e.g., "Palissandre de Madagascar" (Dalbergia spp.) or "Ébène de Madagascar" (Diospyros spp.), some trade relevant species are listed individually in this character. The same holds true for the "true mahoganies" which for practical reasons are treated jointly (Swietenia spp.) in this database.

#3. Synonym(s):/

— Synonyms are obsolete botanical names of trees, superceded by more recent, presently valid names. Since the bibliographical references usually cannot keep pace with the dynamics of name changes in botany, available text books, name lists or technical information leaflets often contain obsolete botanical names. This database strives to always give the most recent, presently valid botanical attribution (family, genus, species). In addition, frequently used older names (synonyms) are listed under this character for better orientation of the user.

#4. Further trade and local names:/

— This character lists additional local, regional and supra regional trade names used with the respective timber.

#5. Code according to DIN EN 13556:/

— The four letter codes given here correspond to those of DIN EN 13556 (Round and sawn timber - Nomenclature of timbers used in Europe; trilingual version, 2003). For timbers not listed in this standard the character has been temporarily marked by "none" until corresponding codes will be developed by the authorities.

#6. Internal <database> code:/

— The three letter codes (acronyms) given here for each of the listed species or species groups are used for internal database purposes, e.g., for names of images facilitating the direct visual comparison of two or more timbers. The files codes.docx and codes.htm contain a complete list of the codes used in the database.

#7. <Status of protection under CITES(EU) regulations: whether listed in annex I(A), II(B) or III(C)>/

1. listed in <CITES> Annex I(A)/

2. listed in <CITES> Annex II(B)/

3. listed in <CITES> Annex III(C)/

4. not protected/

— The protection status of a trade timber (species or species group) is included to enable the user of this database to quickly verify the protection status of an identified taxon. CITES provides three levels of protection:

Taxa considered threatened by extinction are listed in ANNEX I, and trade with plants or parts thereof is strictly prohibited, e.g., Brazilian rosewood (Dalbergia nigra, Papilionaceae).

Taxa considered overexploited but not in immediate danger of extinction may be traded in limited amounts. These are listed in ANNEX II, and trade with plants or parts thereof is subject to strict export and import controls (monitoring), e.g., lignum vitae (Guaiacum spp., Zygophyllaceae) and true mahogany (Swietenia spp., Meliaceae).

ANNEX III contains taxa which have been put under limited protection (level as in ANNEX II) by individual countries, e.g., American cedar (Cedrela odorata, Meliaceae) in Brazil, Bolivia, Guatemala, Peru and Columbia.

A forth character state (not protected) has been added here in order to asign non-CITES timbers their proper category in this database. The accompanying capital letters in parentheses depict the corresponding status under European Union (EU) regulations.

#8. Similar woods: <danger of wrongly identified timbers>/

— This character contains names of timbers that are similar or nearly identical to the CITES protected timber in question and thus largely indistinguishable by macroscopic means.

Geographic distribution

#9. <Geographic distribution:>/

1. Europe <excl. Mediterranean>/

2. Mediterranean incl. N. Africa and Middle East/

3. temperate Asia <China, Japan, former USSR>/

4. India, Pakistan, Sri Lanka/

5. Burma/

6. Thailand, Laos, Vietnam, Cambodia <Indochina>/

7. Indomalesia <Indonesia, Philippines, Malaysia, Brunei, Papua New Guinea, and Solomon Islands>/

8. Pacific Islands <incl. New Caledonia, Samoa, Hawaii, and Fiji>/

9. Australia/

10. New Zealand/

11. tropical Africa/

12. Madagascar & other islands <Mauritius, Reunion & Comores>/

13. southern Africa <south of the Tropic of Capricorn>/

14. North America <north of Mexico>/

15. Mexico and Central America/

16. Caribbean/

17. tropical South America/

18. southern Brazil/

19. temperate South America <incl. Argentina, Chile, Uruguay, and south Paraguay>/

— There is no single ideal way of dividing the world. The above is a mixture of political and biogeographical criteria. It retains the major geographical regions of Brazier and Franklin (1961), but some regions are subdivided so that more precision is possible.

#10. <Geographic distribution, specific countries or regions:>/

— Some of the taxa listed in this database (CITES and non-CITES) have a very restricted geographic distribution, an information sometimes helpful in an identification. Since the rather coarse subdivision of the world in the previous character cannot account for such details, an additional character has been introduced where specific countries and/or regions are entered. For "Brazilian rosewood" (Dalbergia nigra), for instance, its general geographic distribution ("tropical Southamerica", see previous character) is ammended by more specific information ("northeastern and central Brazil").

Growth rings, colour, grain, etc.

#11. Growth ring boundaries <presence>/

1. distinct/

2. indistinct or absent/

— The distinctness of growth ring boundaries is best observed on transverse sections. A growth ring is defined as the increment of wood during a vegetation period. The growth ring boundary delimits each growth increment. Trees growing in temperate or boreal climate are characterized by an annual growth rhythm, a growth ring thus represents and annual increment. In tropical regions, however, the growth rhythm is controlled by seasonal changes (dry season vs. wet season) which may occur once or several times within a 12 month period. Hence, visible growth rings in tropical timbers may not necessarily represent an annual increment.

Growth ring boundaries distinct = growth rings with an abrupt structural change at the boundaries between them, often including a change in fibre wall thickness, i.e., tissue of higher density. Such abrupt structural changes are usually accompanied by corresponding colour changes.

Growth ring boundaries indistinct or absent = growth rings vague and marked by more or less gradual structural changes at their poorly defined boundary, or not visible.

Growth ring boundaries can be marked by one or more of the following structural changes:

a. Thick-walled and radially flattened latewood fibres or tracheids versus thin-walled earlywood fibres or tracheids, e.g. in many temperate softwoods;

b. Marked difference in vessel diameter between latewood and earlywood of the following ring, as in ring-porous and semi-ring-porous woods, e.g. Cedro (Cedrela odorata, Meliaceae) and Teak (Tectona grandis, Verbenaceae);

c. Marginal parenchyma (terminal or initial), e.g. American mahogany (Swietenia spp., Meliaceae);

d. Decreasing frequency of parenchyma bands towards the latewood resulting in distinctly darker fibre zones, e.g. Kasah/Koto (Pterygota spp., Sterculiaceae).

Although absence of growth ring boundaries is a clear enough descriptor, the differences between 'indistinct' and 'distinct' boundaries are somewhat arbitrary, and there are intermediates. Indistinct growth ring boundaries are very common in tropical trees, e.g., Khaya (Khaya spp., Meliaceae) and Ramin (Gonystylus spp., Gonystylaceae).

COMMENTS

Nonperiodical, sporadic occurrence of ring boundaries (due to unusual climatic extremes or traumatic events) should be recorded as 'boundaries indistinct'.

#12. Transition from earlywood to latewood <within a growth ring, softwoods only>/

1. abrupt/

2. gradual/

— This character refers to softwoods only. The transition can be gradual or abrupt.

COMMENTS

The transition between light coloured earlywood and dark coloured latewood is commonly gradual in timbers of "the soft pine" group, e.g., yellow pine (Pinus strobus) and cembra pine (Pinus cembra), and also in spruce and fir (Picea spp., Abies spp.), all Pinaceae. It is commonly abrupt in larch (Larix spp.), Douglas-fir (Pseudotsuga menziesii), and in timbers of the "southern pine" group (Pinus spp., section taeda) (CORE et al. 1979).

CAUTION

Although this feature is commonly employed in softwood identification, its diagnostic power is limited as both states may occasionally be present in a given species or specimen. To slow-grown wood from natural forests (extremely narrow rings) or fast-grown plantation timber (extremely wide rings) this character should not be applied.

#13. <Growth rings, additional observations or comments, e.g. structural changes, latewood colour, etc.:>/

#14. Heartwood <colour> basically/

1. brown <or shades of brown>/

2. red <or shades of red>/

3. yellow <or shades of yellow>/

4. white or grey/

5. black/

6. purple/

7. green/

— The colour of wood may change from the green to the dry state, and that of dry wood is often subject to changes resulting from UV-radiation (light) and/or contact with oxygen (air). For these reasons heartwood colour should always be determined on a freshly planed tangential surface of an at least air-dry specimen.

COMMENTS

The variety of colours, shades, and combinations of heartwood colour make it impossible to categorise all of them. In general, the colour of heartwood is either brown, red, yellow, white, or some shade or combination of these colours. Basically brown heartwood is very common; basically red and basically yellow are rather rare; basically white or grey is rather frequent.

The heartwood colour of many taxa is not restricted to one colour, but presents a combination of colours and, when appropriate, such combinations should be recorded and may be used when identifying an unknown.

The heartwood of most softwoods is yellowish-brown, or shades thereoff, darkening upon exposure to deep brown with a reddish or orange cast. Softwoods without coloured heartwood, i.e., sapwood and heartwood indistinguishable, are, e.g., spruce (Picea abies) and hemlock (Tsuga spp.), both Pinaceae.

Examples of typical colour combinations in hardwoods include light to medium brown, e.g., white oak (Quercus spp., Fagaceae); light pinkish brown, e.g., beech (Fagus sylvatica, Fagaceae); red-brown, e.g., African mahogany (Khaya spp., Meliaceae) and American mahogany (Swietenia spp., Meliaceae); yellow, e.g. ramin (Gonystylus spp., Gonystylaceae); nearly white, e.g., white ash (Fraxinus spp., Oleaceae).

Rare colours such as black, green, orange or purple may be used alone (e.g., as for Diospyros ebenum - Ebenaceae, which has a distinctly black heartwood), and Guaiacum spp., Zygophyllaceae, which has a distictly dark-green heartwood) but more commonly they will be used in combination with other heartwood colours. For example, the combination of brown, red, purple, black, and orange with colour stripes in some rosewoods (Dalbergia spp., Fabaceae-Faboideae).

CAUTION

Be particularly careful when using the feature 'Heartwood basically white to grey', because a whitish coloured sample may be sapwood and not heartwood.

#15. Heartwood <presence of streaks>/

1. with streaks/

2. without streaks /

— Heartwood with streaks is always used in combination with the general heartwood colour. Orange-brown colour stripes are typical of the softwood Paraná pine (Araucaria angustifolia, Araucariaceae). Zebrano (Microberlinia brazzavillensis spp., Fabaceae-Caesalpinioideae) has a light brown heartwood with dark brown stripes. Purple to black striping is characteristic of kingwood (Dalbergia cearensis, Fabaceae-Faboideae).

#16. Sapwood <colour compared to heartwood>/

1. similar to heartwood colour/

2. distinct from heartwood colour/

— The heartwood of many timbers differs in colour from the outer sapwood mantle owing to the deposition of coloured acessory compounds, e.g. cedro (Cedrela odorata, Meliaceae), Patagonian cypress (Fitzroya cupressoides, Cupressaceae), and lignum vitae (Guaiacum spp., Zygophyllaceae). The division between sapwood and heartwood usually follows more or less the growth ring boundaries (WAGENFÜHR 1996). The yellowish ramin (Gonystylus spp., Gonystylaceae), on the other hand, does not feature a colour boundary between heartwood and sapwood.

COMMENT

Sapwood is characterized by the presence of living, physiologically active cells responsible for water conduction and storage of nutrients. When the tree grows older, the inner portions of sapwood are successively transformed into heartwood, i.e. living cells die and their contents (largely sugars and starch) are gradually transformed into organic, often coloured compounds which are deposited mainly in parenchyma cells but also in vessels and, less frequently, in fibres. Simultaneously, other processes take place during heartwood formation such as the permanent closure of pits (softwoods) and the formation of tyloses (in some hardwoods). All these changes essentially serve the effective blockage of pathways in wood to air and water and, with it, the access of harmful microorganisms. At the same time, the newly formed accesory compounds can impart specific properties to the heartwood such as natural durability and reduced moisture exchange with the environment.

Tyloses in the heartwood are particularly well developed in, e.g., black locust (Robinia pseudoacacia, Fabaceae-Faboideae) and white oak (Quercus spp., Fagaceae), to a lesser degree in red oak (Quercus spp., Fagaceae).

ACHTUNG

This feature can only be used when both heartwood and sapwood are present, and it is recorded in combination with the other heartwood colour features.

#17. <Surface texture and wood colour: additional observations or comments>/

#18. Odour <presence>/

1. distinct/

2. indistinct or absent /

— Distinct odour is a useful feature for a number of hardwoods, e.g., many rosewoods (Dalbergia spp., Fabaceae-Faboideae) and cedro (Cedrela odorata spp., Meliaceae). Equally, the differentiation of some softwoods such as the otherwise very similar timbers of Douglas-fir (Pseudotsuga menziesii, Pinaceae) (sour, unpleasant) and larch (Larix spp., Pinaceae) (aromatic, pleasant). Other softwoods with a characteristic odour are, e.g., Western red cedar (Thuja plicata), Florida cedar (Juniperus virginiana), both Cupressaceae, and the true cedars (Cedrus spp., Pinaceae).

In dried wood samples the chemicals responsible for the odour may have volatised from the surface, so it will be necessary to expose a fresh surface, or take other measures to enhance the odour, e.g., add moisture by breathing on the wood, or wet the wood with water and warm it.

COMMENTS

The odour of wood originates from volatile accessory compounds, particularly etherial oils which, in some cases, are extracted and transformed into industrial products, i.e., perfumes, soaps, incense, etc.. Contrary to most temerate hardwoods, many hardwoods from tropical and subtropical regions posses strong odours (pleasant and also unpleasant). In some cases, the pleasant odour of a timber has given rise to a particular end use, e.g. Cedro (Cedrela spp.) and bossé (Guarea cedrata), both Meliaceae, for cigar boxes; or rosewoods (Dalbergia spp., Fabaceae-Faboideae) and sandalwood (Santalum spp., Santalaceae) for jewelry and graces. Other timbers are often used for chests and closets because of their insect repellent properties (odours), e.g., camphorwood (Cinnamomum camphora, Lauraceae) and all junipers (Juniperus spp., Cupressaceae).

CAUTION

Odour is quite variable, and individual perceptions often differ. Therefore, use this feature with caution and only in the positive sense.

Taste is deliberately excluded from the feature list because of safety considerations, particularly a concern that someone may try tasting a wood whose contents could cause a severe allergic reaction.

#19. Wood <weight>/

1. light weight and soft/

2. of medium weight/

3. heavy and hard/

— The density of wood can be determined with sufficient accuracy by measuring and weighing (density in g/cm³). Such a destructive method cannot be applied when dealing with final or semi-manufactured products. In this case one can obtain some information on density by estimating the hardness of the wood by means of a simple test with the thumb nail.

Wood soft or lightweight = thumbnail easily marks the wood surface, e.g. the softwood Patagonian cypress (Fitzroya cupressoides, Cupressaceae) and the hardwood Cedro (Cedrela odorata, Meliaceae).

Wood intermediate in hardness and weight = Thumbnail marks the wood surface to a lesser degree, e.g. ramin (Gonystylus spp., Thymelaeaceae) and true Mahogany (Swietenia spp., Meliaceae).

Wood hard and heavy = Thumbnail marks the wood surface hardly at all, e.g., lignum vitae (Guaiacum spp., Zygophyllaceae).

COMMENT

The weight categories 'light weight', 'medium weight' and 'heavy' correspond approximately to the following density ranges:

leight weight (soft) = up to 0.40 g/cm³

medium weight = 0.41 to 0.75 g/cm³

heavy (hard) = more than 0.75 g/cm³

#20. Surface <whether oily>/

1. oily/

2. not oily /

— The heartwood of some commercial timbers contains rubber-like substances (caoutchouc) in large enough quantities to physically affect the wood surface (wood feels oily or tacky to touch), e.g., lignum vitae (Guaiacum spp., Zygophyllaceae), teak (Tectona grandis, Verbenaceae). Other timbers rich in fats or oils are lime (Tilia spp., Tiliaceae), birch (Betula spp., Betulaceae), scots pine (Pinus spp., Pinaceae). Rubbing the wood surface of these timbers with the flat of the hand (excerting considerable pressure) will give a sensation of stickiness, an admittedly secondary feature which can nevertheless be of some use in wood identification.

#21. Interlocked grain <presence, hardwoods only>/

1. present/

2. absent <= straight grain>/

— Interlocked grain is of common occurrence among tropical hardwoods while extremely rare among those from temperate regions. Softwoods are said to never produce wood with interlocked grain, but practical experience shows very few exceptions to this general rule.

Interlocked grain, sometimes referred to as double spiral grain, describes the phenomenon of the axial elements being aligned at an angle to the vertical axis (spiral grain) but alternately in a right-handed and left-handed direction. Interlocked grain cannot be detected on the transverse and tangential planes, save that on close inspection the grain will be seen as oblique to the longitudinal axis on flat-sawn surfaces. A radial surface, however, will show a striking figure consisting of alternating light and darker stripes ("ribbon" figure), of a width depending on the thickness of each layer. This apparent colour contrast will become even more accentuated with the application of a transparent surface coating. It is important to realise that true colour differences play no part in producing this ribbon figure. It is a strictly optical effect caused by different light reflection in adjacent zones of varying grain angle (GOTTWALD 1958). Interlocked grain is best observed when the wood is split in the radial plane. The line of cleavage follows a typical zigzag course and the longitudinal (radial) plane of cleavage shows alternating ridges and valleys (see illustrations for this character). On planed radial surfaces interlocked grain can be recognized on account of the periodically changing length of the pore lines which are long when the cutting plane is more or less parallel to the grain, and short when the planer cuts the grain at an angle. A very narrow "ribbon" figure can be observed in lignum vitae (Guaiacum spp., Zygophyllaceae), timbers with a regular and wider interlocked grain are, e.g., sapele (Entandrophragma cylindricum), tiama (Entandrophragma angolense), utile (Entandrophragma utile), African mahogany (Khaya spp.), all Meliaceae.

#22. <Grain characteristics, additional observations or comments:>/

Hardwood vs. softwood

#23. Vessels (pores) <presence = hardwood or softwood>/

1. present (= hardwood)/

2. absent (= softwood)/

— The presence of vessels (pores) is a specific feature of hardwoods. Softwoods do not possess vessels, they are composed only of tracheids and parenchyma (storage tissue).

Of all cell types found in hardwoods the vessels have the largest diameters, in part large enough to be easily detected with the unaided eye as pores on a cleancut transverse section, for instance in the earlywood of cedro (Cedrela odorata, Meliaceae). Medium-sized pores are just visible to the unaided eye whereas small pores can only be detected with the help of a hand lens. On longitudinal surfaces vessels form straight to somewhat irregular open canals commonly referred to as "vessel lines".

COMMENT

In hardwoods the vessels serve as conduits of water transported from the roots to the crown. In the vesselless softwoods, the thin-walled earlywood traqueids are mainly responsible for the conduction of water. The function of the thick-walled latewood tracheids is mainly that of mechanical strength, their conductive capacity is very limited.

CAUTION

Although the danger of mistaking a hardwood for a softwood is remote, be nevertheless careful not to confuse hardwoods with extremely small vessels (= pores) with softwoods featuring very large earlwood tracheids.

Vessels (pores)

#24. Wood <porosity, ring vs diffuse>/

1. ring-porous/

2. semi-ring-porous/

3. diffuse-porous/

— Hardwoods can be divided in three groups as regards the specific vessel (= pore) distribution pattern.

Wood ring-porous = wood in which the vessels in the earlywood are distinctly larger than those of the latewood in the previous and of the same growth ring, and form a well defined zone or ring, and in which there is an abrupt transition to the latewood of the same growth ring, e.g., red and white oak (Quercus spp., Fagaceae), ash (Fraxinus spp., Oleaceae), elm (Ulmus spp., Ulmaceae). On tangential faces the rings of coarse earlywood vessels result in a distinctive pattern of V or U-shaped markings, on radial faces they appear as more or less prominent lines.

Wood semi-ring-porous) = wood in which the vessels in the earlywood are distinctly larger than those in the latewood of the previous growth ring, but in which there is a gradual change to narrower vessels in the intermediate and latewood of the same growth ring, e.g., European and American walnut (Juglans regia and J. nigra, Juglandaceae), European and American cherry (Prunus avium and P. serotina, Rosaceae).

Wood diffuse-porous = wood in which the vessels have more or less the same diameter throughout the growth ring, e.g., American mahogany (Swietenia macrophylla, Meliaceae), and ramin (Gonystylus spp., Gonystylaceae). The majority of temperate as well as tropical hardwoods are diffuse-porous. Due to their uniform distribution vessels produce no particular pattern (figure) on longitudinal faces.

COMMENTS

The three features for porosity form an intergrading continuum and many species range from diffuse-porous to semi-ring-porous, or from semi-ring-porous to ring-porous. Porosity is coded independently of vessel arrangement. This implies that woods with a distinct vessel arrangement, as well as those with no specific pattern, may be diffuse-porous.

In some temperate diffuse-porous woods (e.g., Fagus spp., Fagaceae) the latest formed vessels in the latewood may be considerably smaller than those of the earlywood of the next ring, but vessel diameter is more or less uniform throughout most of the ring.

CAUTION

Slow-grown ring-porous woods have narrow growth rings with very little latewood. Be careful not to confuse the closely spaced earlywood zones of slow-grown ring-porous woods with a tangential pattern, or to interpret such woods as diffuse-porous.

#25. Earlywood pore ring <uniseriate vs multiseriate>/

1. uniseriate/

2. multiseriate/

— A further characteristic of the earlywood ring of ring-porous woods is its depth (in radial direction), i.e., how many vessels wide the ring is. This character can sometimes be useful in identifying certain trade timbers, e.g., teak (Tectona grandis, Verbenaceae) and cedro (Cedrela odorata, Meliaceae), or individual species within a given genus, e.g. the American elms (Ulmus spp., Ulmaceae).

#26. Vessels (pores) arranged in <pattern, in ringporous woods only latewood>/

1. no specific pattern /

2. tangential bands/

3. a radial pattern/

4. a diagonal pattern/

5. a dendritic pattern/

— 'No specific pattern' is a term of convenience; the majority of hardwoods does not feature a specific vessel arrangement.

Vessels in tangential bands = vessels arranged perpendicular to the rays and forming short or long tangential bands; these bands can be straight or wavy, continuous or interrupted, e.g., elm (Ulmus spp., Ulmaceae), hackberry (Celtis spp., Ulmaceae), and sen (Kalopanax pictus, Araliaceae).

Vessels in a radial pattern = vessel assemblies arranged in radial lines (parallel to the rays), separated by vesselless zones, e.g., many Sapotaceae (Chrysophyllum spp., and others). The radial pattern can be recognized not only on a transverse surface but also on the radial longitudinal plane on account of groups of closely spaced pore lines.

Vessels in a diagonal pattern: vessel assemblies arranged in an intermediate (oblique) pattern between tangential and radial, e.g., many of the diffuse-porous eucalypt species (Eucalyptus spp., Myrtaceae) and the latewood vessel groups of the ring-porous red and white oaks (Quercus spp., Fagaceae); this pattern is often accompanied by a periodic change in direction of larger pore assemblies from right to left and vice versa ('herringbone' pattern).

Vessels in dendritic pattern = vessels arranged in a branching pattern, forming distinct tracts, separated by areas devoid of vessels, e.g., latewood pore groups of white oaks (Quercus spp., Fagaceae).

PROCEDURE

Vessel distribution patterns (tangential, diagonal/radial, dendritic) are determined from the cross section at a low magnification, and are recorded only where there is a distinct pattern. In ring-porous woods, only the intermediate and latewood are examined. The ring of vessels at the beginning of the growth ring of ring-porous woods is NOT considered when determining vessel distribution patterns.

COMMENTS

These features often occur in combination. Vessel arrangement in some woods intergrades between tangential and diagonal. Diagonal and dendritic often intergrade, e.g., in latewood of the ring-porous white oaks (Quercus spp., Fagaceae). All applicable features should be recorded.

The expression of vessel arrangement also depends on the width of the growth rings. In very narrow rings (slow-grown wood) of ring-porous woods specific vessel patterns often become indistinct.

#27. Vessels (pores) <solitary vs grouped>/

1. exclusively solitary <more than 90%>/

2. in multiples <mixed solitary and multiples or exclusively multiples>/

— Vessels exclusively solitary = 90% or more of the vessels are completely surrounded by other elements, i.e., 90% or more appear not to contact another vessel, as viewed in cross section, e.g. many eucalypts (Eucalyptus spp., Myrtaceae). In ring-porous woods only the earlywood pores should be considered. Earlywood vessels are typically solitary in red and white oaks (Quercus spp., Fagaceae).

Vessels in multiples = mixed solitary (<90%) and multiple vessels (=pores) or vessels (=pores) exclusively in multiples.

CAUTION

Care is needed to recognise the following as not being multiples: closely associated solitary vessels, as in some species of eucalypts Eucalyptus (Myrtaceae) in which vessels (pores) are virtually all solitary but so closely spaced in oblique tracts that they appear as large pore multiples.

#28. Vessels (pores) <arrangement of multiples> commonly/

1. in short (2–3 vessels) radial rows/

2. in radial rows of 4 or more/

3. in clusters/

— In radial multiples = 2 or more vessels (= pores) are in direct radial contact, i.e., they have common walls which are flattened at the interface.

In clusters: 3 or more vessels (= pores) are clustered in irregular groups and have direct radial as well as tangential contact.

Short radial multiples of 2–3 vessels in combination with a variable number of solitary vessels is the most common form of vessel grouping, e.g., ramin (Gonystylus spp., Gonystylaceae).

COMMENTS

Character state 2 'radial multiples of 4 or more common' should be used only when radial multiples of 4 or more are an obvious feature of the transverse section, e.g. Donella pruniformis (Sapotaceae). State 3 'clusters common' applies only when clusters are frequent enough that they are easily observed during a quick scan of a cross section. Clusters and radial multiples of 4 or more are not mutually exclusive and can occur in combination. Woods with vessels in tangential bands often have clusters.

#29. <Qualitative vessel (pore) features, additional observations or comments:>/

#30. Vessels <average size (tang. diameter),classes>/

1. small <not visible to the naked eye = less than 80 µm>/

2. medium <just visible to the naked eye = 80–130 µm>/

3. large <commonly visible to the naked eye = more than 130 µm>/

— PROCEDURE

Tangential vessel diameter is measured in transverse sections. Vessels are selected for measurement with care not to bias the selection towards the larger or smaller vessels.

In ring-porous woods only measure and record the larger size class (earlywood). Information about tangential diameters of the smaller vessels would be useful in a description.

In semi-ring-porous woods, measure along a radial transect through a growth ring.

It is recommended to enter a range of values, e.g., 100 – 150 µm (0.10 – 0.15 mm).

COMMENT

small vessels (= pores) cannot be detected with the unaided eye, a handlens is required.

medium-size vessels (= pores) are just visible with the unaided eye, whereas large vessels (= pores) are easily visible with the unaided eye.

#31. Vessels <number of vessels per mm² - frequency classes>/

1. very few <less than 5 per mm²>/

2. few <5–20 per mm²>/

3. moderately numerous <20–40 per mm²>/

4. numerous <40–100 per mm²>/

5. very numerous <more than 100 per mm²>/

— PROCEDURE

All vessels are counted as individuals, e.g., a radial multiple of 4 would be counted as four vessels (Wheeler 1986). Count all the vessels in at least five (preferably ten) fields of appropriate size (depending on vessel diameter and distribution). For woods with small diameter vessels use fields of 1 mm², for woods with large vessels that are widely spaced use fields of at least 5 mm². Of the vessels that are partially in the field of view, only 50% are included in the count. If vessel frequency is very low, examine enough fields to account for local variations, and preferably count at least 100 vessels. A transparency with defined frames placed on the wood surface is very useful for counting vessel frequency.

It is recommended to enter a range of values, e.g., 18 – 28/mm².

COMMENT

Vessel frequency is not computed for ring-porous woods, or for woods with vessels in definite tracts, e.g., dendritic patterns as seen in the latewood of white oak (Quercus spp., Fagaceae), or tangential bands as seen in elm (Ulmus spp., Ulmaceae).

#32. <Quantitative vessel (pore) data, additional observations or comments:>/

#33. Tyloses <presence, in heartwood vessels (pores)>/

1. present/

2. absent/

— The presence of tyloses can be very useful for wood identification. In ring-porous woods, it is best to examine the earlywood vessels for tyloses. They are often absent from or simply invisible in small diameter latewood vessels.

WARNING: Use this character only for heartwood!

PROCEDURE

Tyloses are best recognised on account of strong light reflection from the numerous facets producing a distinctive glitter (much like the iridescent glitter of soap bubbles) (GOTTWALD 1958). Likewise, tyloses can be observed on longitudinal surfaces filling the vessel lines. Surfaces should be carefully planed, never sanded as wood dust settles in the vessel lines and obscures the presence of tyloses. Tyloses may be few or many, ranging from all vessels filled with many tyloses to a few vessels with a few tyloses.

COMMENT

For timbers containing tyloses in heartwood both character states "present" AND "absent" are coded in the database. This way the character loses its diagnostic power but possible matches will not be eliminated from the list of remaining taxa when an unknown specimen to be identified is only sapwood and the character state "absent" is coded by the user.

COMMENT

Tyloses = outgrowths from an adjacent ray or axial parenchyma cell through a pit in a vessel wall, partially or completely blocking the vessel lumen. Absence of tyloses is not diagnostic; for identification this feature can be used only in the positive sense.

#34. Other deposits in heartwood vessels (pores)/

1. present/

2. absent/

— Other heartwood deposits = a wide variety of organic and, rarely, inorganic chemical compounds, which are variously coloured (white, yellow, red, brown, black).

WARNING: Use this character only for heartwood!

COMMENTS

In cross sections, deposits appear to completely fill some vessel lumina; in longitudinal sections, deposits often appear to collect at the end of vessel elements but can also completely fill the vessels over longer stretches, e.g., ekki (Lophira alata, Ochnaceae). Deposits often can be seen clearly by examining the woods with a hand lens, more easily on longitudinal faces (in vessel lines) than in cross section. In a description it is appropriate to indicate their abundance and colour as well as their chemical nature. Such information may be documented as comment. See Hillis (1987) for more information on the chemistry of deposits.

COMMENT

For timbers containing heartwood extractives both character states "present" AND "absent" are coded in the database. This way the character loses its diagnostic power but possible matches will not be eliminated from the list of remaining taxa when an unknown specimen to be identified is only sapwood and the character state "absent" is coded by the user.

#35. <Tyloses and other deposits in heartwood vessels: additional observations or comments, eg. type, colour etc.>/

Axial parenchyma

#36. Axial parenchyma <presence>/

1. present <visible to the naked eye or with a magnifying lens>/

2. not visible/

— Axial parenchyma (= storage tissue) is oriented vertically, i.e. parallel to the stem axis. It serves the transport and storage of nutrients in the living tree. Axial parenchyma is often recognised (but by no means always) on account of its lighter colour (thin-walled cells with high light reflectivity) and the resulting colour contrast with the surrounding darker ground tissue (fibres with thicker cells walls). Transverse surfaces are best suited for observing specific patterns of axial parenchyma tissue. Axial parenchyma is present in nearly all hardwoods and softwoods, but is often so sparingly developed that observation is impossible even with a hand lens, e.g., African mahogany (Khaya spp., Meliaceae). If sufficiently developed, axial parenchyma is a highly diagnostic feature forming distinct patterns of variable expression. Combinations of the types and patterns described below may be present in a given wood.

Axial parenchyma bands = continuous tangential lines, variable in terms of straightness, width, frequency, and with regard to specific patterns formed with the rays running perpendicular to the bands.

Axial parenchyma sheaths = defined patches or sheaths associated with and, in most cases, completely surrounding the vessels (paratracheal). The sheaths assume specific forms (contours) such as complete (vasicentric) or incomplete (unilateral) rings, and lozenges (aliform). If sheaths around adjacent, closely spaced vessels coalesce, the descriptive term "confluent" is used (for details see the notes accompanying the respective features).

Other forms of axial parenchyma

Diffuse and diffuse-in-aggregates = single parenchyma strands or pairs of strands distributed irregularly among the fibrous elements of the wood (diffuse); or parenchyma strands grouped into short discontinuous tangential or oblique lines (diffuse-in-aggregates). Diffuse axial parenchyma is invisible macroscopically and therefore not part of this character list. For notes on axial parenchyma 'diffuse-in-aggregates' see under the respective feature (other forms of axial parenchyma).

COMMENT

When identifying an unknown, use the most obvious type of axial parenchyma pattern first and then the less evident type or types. Be sure to use a broad field of view when determining the predominant parenchyma pattern(s) from the transverse section. Many combinations of axial parenchyma types can be observed in a single timber.

#37. Axial parenchyma <whether banded>/

1. <typically> banded/

2. not banded/

— This feature should be coded only when parenchyma bands constitute a distinct characteristic of the transverse section. Parenchyma bands may be mainly independent of the vessels (apotracheal), definitely associated with the vessels (paratracheal), or both. Bands may be wavy, straight, continuous or discontinuous (the latter often intergrading with confluent (see axial parenchyma 'confluent').

Prominent bands will cause, like all concentric structures, V-shaped or U-shaped markings on tangential faces, with a more or less regular (straight bands) or rather jagged (undulating bands) course.

#38. Parenchyma bands <whether marginal>/

1. exclusively marginal (or seemingly marginal)/

2. not (only) marginal/

— Parenchyma bands marginal = parenchyma bands occurring at relatively regular intervals and forming a more or less continuous layer of variable width at the margins of a growth ring, either at the beginning (initial) or the end (terminal) of the growth season. In some timbers marginal bands are the only type of axial parenchyma visible macroscopically, e.g., true mahogany (Swietenia spp., Meliaceae). In others they occur in combination with other types of axial parenchyma, e.g., with aliform parenchym as in afzelia (Afzelia spp., Fabacaeae-Caesalpinioideae), short wavy bands as in utile (Entandrophragma utile, Meliaceae), numerous continuous bands as in kasah/koto (Pterygota spp., Sterculiaceae). The width of marginal parenchyma bands varies considerably. Bands are often wide in ring-porous timbers when earlywood pores are enclosed in the band, e.g., teak (Tectona grandis, Verbenaceae) and cedro (Cedrela odorata, Meliaceae); they are narrow in many diffuse-porous timbers, e.g., andiroba (Carapa guianensis, Meliaceae).

Seemingly marginal bands are similar in appearance to true marginal bands but do not constitute growth ring boundaries, e.g., the bands associated with resin canals in Dipterocarp timbers such as red meranti (Shorea spp., sect. rubroshorea) and balau (Shorea spp., sect. shorea).

Axial parenchyma bands which are not marginal usually occur in large numbers and at short intervals (also between marginal bands), and often follow a more irregular course (wavy, interruped) than marginal bands, e.g., rubberwood (Hevea brasiliensis, Euphorbiaceae), and ekki (Lophira alata, Ochnaceae).

#39. Parenchyma bands <width>/

1. narrow/

2. wide/

— Parenchyma in narrow bands or lines = usually not or only barely visible to the unaided eye, e.g., andiroba (Carapa guianensis, Meliaceae).

Parenchyma bands wide = usually visible to the unaided eye, e.g., Kosipo (Entandrophragma candollei, Meliaceae), ekki (Lophira alata, Ochnaceae).

#40. Parenchyma bands <pattern with rays>/

1. forming a reticulate pattern with rays <of same width>/

2. forming a scalariform pattern <with wider rays>/

3. much wider than rays/

— Parenchyma reticulate = parenchyma in continuous tangential lines of approximately the same width as the rays, regularly spaced and forming a network with them. The distance between the rays is approximately equal to the distance between parenchyma bands, e.g., rubberwood (Hevea brasiliensis, Euphorbiaceae).

Parenchyma scalariform = parenchyma in fairly regularly spaced fine lines or bands, arranged horizontally or in arcs, appreciably narrower than the rays and with them producing a ladder-like appearance in cross section. The distance between the rays is greater than the distance between parenchyma bands, e.g., ntom (Pachypodanthium staudtii and most other Annonaceae.

Parenchyma bands much wider than rays = as per feature descriptor, e.g., ekki (Lophira alata, Ochnaceae) and wengé (Millettia laurentii, Fabaceae-Faboideae).

#41. <Banded axial parenchyma, additional observations or comments:>/

#42. Other macroscopically visible types of axial parenchyma: <except bands>/

1. diffuse-in-aggregates <zonate>/

2. vasicentric <paratracheal>/

3. aliform <paratracheal>/

4. confluent/

5. none/

— Axial parenchyma diffuse-in-aggregates = parenchyma strands grouped into short discontinuous tangential or oblique lines in, e.g., walnut (Juglans regia and J. nigra, Juglandaceae) and durian (Durio spp., Sterculiaceae), in both timbers intergrading with fine bands; difficult to observe because of little colour contrast in, e.g., obeche (Triplochiton scleroxylon, Sterculiaceae). On longitudinal surfaces this type of axial parenchyma is macroscopically invisible.

Axial parenchyma vasicentric = parenchyma cells forming a complete circular to oval sheath around a solitary vessel or vessel multiple, e.g., gedu nohor (Entandrophragma angolense, Meliaceae).

Axial parenchyma aliform = parenchyma sheath surrounding the vessel and with lateral extensions forming a lozenge (for subtypes and examples see the following character), e.g., afzelia (Afzelia spp., Fabaceae-Caesalpinioideae).

Axial parenchyma confluent = coalescing vasicentric or aliform parenchyma surrounding or to one side of two or more vessels, and often forming irregular bands, e.g. iroko (Milicia excelsa, Moraceae).

On longitudinal surfaces well developed vasicentric and aliform axial parenchyma is often visible as a lighter coloured lining of the vessel lines.

COMMENT

The various types of axial parenchyma described here can co-occur and/or intergrade in one and the same timber. Some posses vasicentric, aliform and confluent parenchyma; confluent parenchyma can intergrade with parenchyma bands and should then be used in combination with 'width of parenchyma bands', e.g., wengé (Millettia laurentii, Papilionaceae).

#43. Aliform parenchyma <type>/

1. of the lozenge type/

2. winged/

— Axial parenchyma lozenge-aliform = parenchyma surrounding or to one side of the vessel with lateral extensions forming a diamond-shaped outline, e.g., afzelia (Afzelia spp., Fabaceae-Caesalpinioideae).

Axial parenchyma winged-aliform = parenchyma surrounding or to one side of the vessel with lateral extensions being elongated and narrow, e.g., ramin (Gonystylus spp., Gonystylaceae).

#44. <Axial parenchyma, additional observations or comments:>/

Rays

#45. Rays <ray width as observed in transverse section>/

1. narrow/

2. wide (also in combination with narrow rays)/

— Wood rays occur in practically all softwoods and hardwoods of commercial significance. Size and frequency of rays, however, vary considerably and may constitute a very useful diagnostic feature, particularly the very wide and high rays. Ray width is determined in transverse section and can roughly be subdivided into two macroscopically distinguishable size classes:

Rays narrow = generally not to be detected with the unaided eye because of their small size. All softwoods, characterised by very narrow (nearly all uniseriate) rays belong to this category. Narrow rays, though not necessarily uniseriate, are also found in most hardwoods, e.g., true mahogany (Swietenia macrophylla), sapele (Entandrophragma cylindricum, both Meliaceae), and rubberwood (Hevea brasiliensis, Euphorbiaceae).

Rays broad (also in combination with narrow rays) = easily visible with the unaided eye, about 0,5 mm (or more) in width, e.g., red oak and white oak (Quercus spp., Fagaceae), and beech (Fagus sylvatica, Fagaceae). Aggregate rays also count as wide rays. Actually, they constitute rays composed of a number of individual rays so closely associated with one another that they appear macroscopically as a single large ray. The individual rays are separated by axial elements, e.g., alder (Alnus spp., Betulaceae), hornbeam (Carpinus betulus, Betulaceae).

In the case of rays occurring in two distinct sizes (see next character) only the large rays are considered, e.g., oak (Quercus spp., Fagaceae).

#46. Rays <presence of two distinct sizes>/

1. of two distinct sizes/

2. of uniform size /

— Rays of two distinct sizes = when viewed in transverse or tangential section, rays form two distinct populations by their width and usually also by their height, e.g., red and white oak (Quercus spp., Fagaceae), and alder (Alnus spp., Betulaceae - the large ones being aggregate rays).

COMMENT

Since aggregate rays cannot be separated macroscopically from normal (solid) large-size rays, their presence in combination with narrow rays is coded as 'rays of two distint sizes present' in this database. Although in strictly morphological terms this interpretation of aggregate rays is not correct, it nevertheless serves its purpose in macroscopic identification.

CAUTION

For determining whether a wood has rays of two distinct sizes consult both tangential and cross section. However, be very careful because in cross sectional view the long uniseriate wings of heterocellular multiseriate rays might be interpreted incorrectly as narrow rays.

#47. Large rays <height as observed in tangential plane>/

1. commonly less than 1 mm high/

2. commonly between 1 mm and 5 mm high/

3. commonly over 5 mm and up to several cm high/

— Ray height is best determined on tangential surfaces if the spindle-shaped contours of the rays show sufficient color contrast.

Rays commonly up to 1 mm high is among the more common feature in trade timbers.

Ray height between 1 mm and 5 mm = as per feature descriptor, e.g., beech (Fagus sylvatica, Fagaceae) and plane (Platanus spp., Platanaceae).

Ray height more than 5 mm = as per feature descriptor, e.g., oak (Quercus spp., Fagaceae). The high and very high rays (character states 2 and 3) constitute very useful tools in macroscopic wood identification. Large rays more than 5 mm and up to several cm high also includes the aggregate rays in several common hardwoods, e.g., alder (Alnus spp., Betulaceae), hornbeam (Carpinus betulus, Betulaceae), hazel (Corylus spp., Corylaceae).

COMMENT

If the spindle-shaped contours of the rays are difficult to detect because of insufficient colour contrast also use split radial surfaces and search for the ribbon-like bands of rays which may be more easily visible due to the specific light reflection ('silver grain').

#48. <Rays, additional observations or comments:>/

Storied structure

#49. Storied structure <presence>/

1. present/

2. absent /

— Storied structure = cells arranged in tiers (horizontal or slightly inclined series) as viewed on the tangential surface.

PROCEDURE

The presence of storied structure can only be determined from the tangential surface, not from the radial surface!

Tiers of rays are often visible with the unaided eye or a hand lens, and appear as fine horizontal striations or 'ripple marks' on the tangential surface, e.g. lignum vitae (Guaiacum spp., Zygophyllaceae) and in some specimens of true mahogany (Swietenia) spp., Meliaceae).

COMMENT

Not only the rays can be storied. In some woods all elements are storied, while in others various combinations of elements are storied, e.g., axial parenchyma, or combinations of tissues (axial parenchyma + fibres + vessels + low rays, but not the high rays . However, since differentiation of individual tissues, whether storied or not, is very difficult to accomplish macroscopically, 'storied structure' only refers to its general presence or absence.

CAUTION

There is also variability within species and specimens. For instance, in some samples of true mahogany (Swietenia) spp., Meliaceae) and sapele (Entandrophragma cylindricum, Meliaceae) rays are definitely storied, in others irregularly storied, and in still others rays are not storied. Hence, this feature should be used only in the positive sense.

#50. Tiers <arrangement of storied elements>/

1. regular (horizontal or slightly inclined)/

2. irregular/

— Rays and/or axial elements irregularly storied = stories of rays and/or axial elements not horizontal or slightly inclined, but wavy (in echelon), or only locally present, e.g., sapele (Entandrophragma cylindricum, Meliaceae).

#51. Tiers <number of tiers (rays) per axial millimetre>/

per axial millimetre/

— COMMENT

The number of ray tiers per mm can be useful in distinguishing genera and species, especially in the many Fabaceae with storied structure.

It is recommended to enter a range of values, e.g., 4–7 tiers per mm.

#52. <Storied structure, additional observations or comments:>/

Resin canals

#53. Normal resin canals <presence>/

1. present/

2. absent /

— The presence of axial resin canals is best determined on a transverse section; on longitudinal surfaces their presence (axial and radial) may be inferred from dark spots (resin exuding from canals) or brightly coloured lines (axial canal lumina filled with crystallized resin).

COMMENTS

A resin canal is a tubular intercellular duct, generally containing secondary plant products (resins) secreted by surrounding epithelial cells, and being part of the normal, e.g., genetically predetermined wood structure (as opposed to traumatic canals). The canals may be oriented axially (axial or vertical intercellular canal), or radially (radial or horizontal intercellular canal, within a ray). Synonyms: gum duct, resin duct.

The presence of axial resin canals is best determined on a transverse section; on longitudinal surfaces their presence (axial and radial) may be inferred from dark spots (resin exuding from canals) or brightly coloured lines (axial canal lumina filled with crystallized resin). Since axial resin canals are essentially longitudinal tubes, their appearance in cross section can be very similar to that of the vessels, or pores. In hardwoods they may be distinguished from pores only by means of a special arrangement, e.g., in continuous tangential bands, by consistent differences in diameter, or by exuding resin. The often irregular outline of resin canals (as opposed to vessels, resin canals have no cell walls) may also be of some help in distinguishing them from vessels of similar size. In hardwoods with a diffuse distribution of resin canals, having a diameter similar to that of the vessels, e.g., tchitola (Pterygopodium oxyphyllum, Fabaceae-Caesalpinioideae) their presence is all but impossible to assert macroscopically unless betrayed by exuding resin. Resin canals occur in softwoods and hardwoods. In softwoods they are restricted to members of the Pinaceae family, notably in some important trade timbers, e.g., Douglas-fir (Pseudotsuga menziesii), spruce (Picea spp.), larch (Larix spp.) und all pines (Pinus spp.). Among the frequently traded hardwoods with macroscopically visible resin canals are, e.g., red meranti (Shorea spp., sect. rubroshorea) and balau (Shorea spp., sect. shorea) of the Dipterocarp family.

CAUTION

Timbers which do not have normal resin canals may still form so-called "traumatic" resin canals, e.g., true fir (Abies spp.), true cedar (Cedrus spp., both Pinaceae), black cherry (Prunus serotina, Rosaceae), marupá (Simarouba amara, Simaroubaceae), and most of the mahogany timber yielding Meliaceae. Traumatic canals form as a response to injury and therefore may not occur consistently in a given taxon. Traumatic resin canals differ from normal canals, if at all, by their large size, irrgular ouline, and by clustering into short tangential groups.

#54. Normal resin canals <arrangement>/

1. in long tangential lines/

2. in short tangential lines/

3. diffuse/

— The presence of axial resin canals is best determined on a transverse section.

Normal axial canals in long tangential lines = more than five canals in a line, e.g., red meranti (Shorea spp., sect. rubroshorea, Dipterocarpaceae) and many other Dipterocarp timbers. Synonym: Concentric axial canals.

Normal axial canals in short tangential lines = two to five axial canals in a line, e.g., keruing (Dipterocarpus spp., Dipterocarpaceae). Long and short tangential lines may also occur jointly, e.g., balau (Shorea spp., sect. shorea, Dipterocarpaceae).

Norma axial canals diffuse = randomly distributed solitary canals, e.g., tchitola (Pterygopodium oxyphyllum, Fabaceae-Caesalpinioideae).

#55. Normal resin canals <size>/

1. large/

2. small/

— In softwoods the size (diameter as estimated from transverse sections) of axial resin canals is, in some instances, a complementary feature to distinguish between certain timbers. The rather crude distinction between "large" and "small" is arbitrarily defined around the threshold of about 100 µm: canals with more than 100 µm in diameter are considered large, i.e., visible with the unaided eye, e.g., soft pines (Pinus spp., section strobus), southern pines (Pinus spp., section taeda), radiata pine (Pinus radiata). Canals with less than 100 µm in diameter are considered small, i.e. generally difficult to discern with the unaided eye, e.g. Douglas fir (Pseudotsuga menziesii), larch (Larix spp.), spruce (Picea spp.).

Traces of large axial canals can also be observed on longitudinal surfaces while those of small axial canals are practically invisible unless betrayed by exuding resin.

#56. <Normal resin canals, additional observations or comments:>/

Included phloem

#57. Included phloem <presence>/

1. present/

2. absent /

— The presence of included "phloem" (scientific term for bark tissue) constitutes an important character in wood identification. Included phloem is a rare phenomenon and thus its presence reduces considerably the number of possible timbers during an identification. The following distribution patterns (see next character) are based on its appearance on clean-cut transverse surfaces.

Among the timbers at present under CITES protection only one (aloewood = Aquilaria malaccensis, Thymelaeaceae) features included phloem. Despite the fact that aloewood is not a widely traded timber it is included in the current version of the database.

#58. Included phloem <arrangement>/

1. concentric/

2. diffuse/

— Included phloem, concentric = Phloem strands in tangential bands alternating with zones of xylem , e.g., Avicennia spp. (Avicenniaceae).

Included phloem, diffuse = scattered, isolated phloem strands. The phloem strands may be surrounded by parenchyma or imperforate tracheary elements, e.g., Strychnos nux-vomica (Loganiaceae).

COMMENTS

Included phloem of the concentric type very often intergrades with diffuse included phloem, e.g., aloewood (Aquilaria spp. and Gyrinops spp., Thymelaeaceae); in all cases of doubt use both feature states. In species with concentric included phloem the phloem bands may branch and anastomose.

#59. <Included phloem, additional observations or comments:>/

Physical and chemical tests

#60. Heartwood <fluorescence>/

1. fluorescent/

2. not fluorescent/

— Heartwood fluorescent = wood surface fluorescing when illuminated with longwave ultraviolet light, e.g., with a strong yellowish or greenish fluorescence in afzelia (Afzelia pachyloba, Fabaceae-Caesalpinioideae) and robinia (Robinia pseudoacacia, Fabaceae-Faboideae); with a slight tinge of orange fluorescence in opepe (Nauclea diderrichii, Rubiaceae).

PROCEDURE

Samples for testing fluorescence must be freshly surfaced; simply removing some shavings with a knife is sufficient for exposing a fresh surface. Place samples under longwave (365 nm) ultraviolet (UV) light at a distance of 10 to 25 cm. A high-intensity longwave UV lamp and observation in a darkened room is recommended.

COMMENTS

Fluorescent samples generally appear yellowish or greenish under the UV lamp, although some species show slight tinges of orange, pink, or violet.

Samples that are not fluorescent may reflect some of the UV light making the surface appear slightly blue or purple, e.g., doussié rouge (Afzelia bipindensis, Fabaceae-Caesalpinioideae). Some timbers with a yellowish heartwood, such as ramin (Gonystylus spp., Gonystylaceae), are not fluorescent, but may seem to have a weak yellow fluorescence because of reflection. See MILLER (2007) and AVELLA & al. (1989) for a survey of fluorescence in the dicotyledons.

CAUTION

This feature applies only to naturally occurring fluorescence and not to fluorescence associated with decay or pathological infections. Wood infected with decay organisms may fluoresce with streaks, spots, or a mottled appearance, e.g., wetwood of Canadian aspen (Populus tremuloides, Salicaceae) produces yellow fluorescent streaks. Naturally occurring fluorescence appears more uniform.

#61. Water extract <fluorescence>/

1. fluorescent/

2. not fluorescent/

— PROCEDURE

Add enough thin heartwood shavings to cover the bottom of a clean vial. Do not use splinters or chips, because the extraction time is much longer than for shavings. Cover shavings to a depth of approximately 20 mm (approximately 5 ml) with distilled water that is buffered at a pH of 6.86. Packets of buffering agents are available from most scientific supply companies so that only the contents of a packet need to be added to 500 or 1000 ml of distilled water to obtain the desired pH. Cover the vial and shake vigorously for 10 to 15 seconds. Allow the shavings and solution to stand for 1 to 2 minutes, and then hold the vial under a longwave (approximately 365 nm) UV lamp for extract fluorescence. Generally, water extracts that fluoresce are yellowish, bluish, and sometimes they are greenish.

COMMENT

Examples of woods yielding water extracts that fluoresce a brilliant blue are opepe (Nauclea diderrichii, Rubiaceae) and satiné (Brosimum rubescens, Moraceae). Other examples with a positive but weak fluorescence of the water extract are: maple (Acer spp., Aceraceae), walnut (Juglans spp., Juglandaceae), and robinia (Robinia pseudoacacia, Fabaceae-Faboideae).

#62. Water extract <colour, basically>/

1. colourless to brown <or shades of brown>/

2. red <or shades of red>/

3. yellow <or shades of yellow>/

4. purple/

5. green/

— PROCEDURE

After determining the fluorescence of the water extract, place the vials on a hotplate and bring the solution to a boil. As soon as the solution boils, remove the vial and immediately determine colour.

COMMENTS

Water extract basically colourless to brown or shades of brown is the most common of the water extract feature colours.

An example of woods with water extract basically red or shades of red is bubinga (Guibourtia spp., Fabaceae-Caesalpinioideae).

Examples of woods with water extract basically yellow or shades of yellow include common alder (Alnus glutinosa, Betulaceae), idigbo (Terminalia ivorensis, Combretaceae), and robinia (Robinia pseudoacacia, Fabaceae-Faboideae).

#63. Heartwood extractives <whether leachable by water>/

1. leaching out when in contact with water/

2. not leachable by water /

— Heartwood extractives leachable in water.

This character was included for practical reasons, i.e., to allow a search in the database for timbers whose heartwood extractives are easily washed out when exposed to standing or running water. Failure to recognise, or know about, this particular property of some timbers used primarily in outdoor construction may cause considerable problems, particularly in the context of the increasing usage of water-based surface coatings.

PROCEDURE

Completely saturate a white paper towel or filter paper with water. Place the wood specimen with a freshly planed or sawn surface on the wet substrate. Wait for about 15 min, remove the specimen and evaluate the mark on the substrate as to colour and intensity. Timbers known for their water soluble, i.e., leachable extractives are, e.g., idigbo (Terminalia ivorensis, Combretaceae - bright yellow), merbau (Intsia spp., Fabaceae-Caesalpinioideae - dirty reddish-brown), balau (Shorea spp., section shorea, Dipterocarpaceae - from lemon yellow to dirty brown depending on species).

#64. Ethanol extract <fluorescence>/

1. fluorescent/

2. not fluorescent/

— PROCEDURE

Add enough thin heartwood shavings to cover the bottom of a clean vial. Do not use splinters or chips, because the extraction time is much longer than for shavings. Cover shavings to a depth of approximately 20 mm (approximately 5 ml) with 95% ethanol. Cover the vial and shake vigorously for 10 to 15 seconds. Allow the shavings and solution to stand for 1 to 2 minutes, and then hold the vial under a longwave (approximately 365 nm) UV lamp for extract fluorescence. Generally, extracts that fluoresce are yellowish or bluish, but sometimes they are greenish.

COMMENT

Examples of woods yielding an ethanol extract with bright fluorescence are opepe (Nauclea diderrichii, Rubiaceae) and satiné (Brosimum rubescens, Moraceae). A wood with weaker fluorescence of the ethanol extract, but still positive, is ekki (Lophira alata, Ochnaceae).

Sometimes the water extract of a species fluoresces, but its ethanol extract does not. More often, the ethanol extract fluoresces, while the water extract does not, e.g., afzelia (Afzelia quanzensis, Fabaceae-Caesalpinioideae).

#65. Ethanol extract <colour, basically>/

1. colourless to brown <or shades of brown>/

2. red <or shades of red>/

3. yellow <or shades of yellow>/

4. purple/

5. green/

— PROCEDURE

After determining the fluorescence of the ethanol extract, place the vials on a hotplate and bring the solution to a boil. As soon as the solution boils, remove the vial and immediately determine colour.

COMMENTS

Ethanol extract basically colourless to brown or shades of brown (state 1) is the most common.

A wood with ethanol extract basically red or shades of red (state 2) is afzelia (Afzelia spp., Fabaceae-Caesalpinioideae).

Examples of woods with ethanol extract basically yellow or shades of yellow (state 3) include maple (Acer spp, Aceraceae) and pear (Pyrus communis, Rosaceae).

For more information on fluorescence and colour of water and ethanol extracts see Dyer (1988) and Quirk (1983).

#66. <Colour and fluorescence of extracts, additional observations or comments:>/

#67. Froth test <whether positive>/

1. positive/

2. negative /

— The froth test is used for indicating the presence of natural saponins in the wood.

PROCEDURE

Add enough thin heartwood shavings to cover the bottom of a clean vial. Do not use splinters or chips, because the extraction time is much longer than for shavings. Cover shavings to a depth of approximately 20 mm (approximately 5 ml) with distilled water that is buffered at a pH of 6.86. Packets of buffering agents are available from most scientific supply companies so that only the contents of a packet need to be added to 500 or 1000 ml of distilled water to obtain the desired pH.

Cover the vial and shake vigorously for 10 to 15 seconds. If natural saponins are present in large amounts, tiny bubbles or 'froth' (like foam in a glass of beer) will be formed. Allow the vial to stand for approximately 1 minute from the end of shaking. If 'froth' still completely covers the surface of the solution, the test is positive. If 'froth' or bubbles form and then disappear within 1 minute, the test is negative. If only some froth remains around the edge of the vial (i.e., forming a ring of 'froth', but does not cover the entire surface, the test is weakly positive.

COMMENTS

Positive 'froth' test reactions are produced by, e.g., afzelia (Afzelia spp., Fabaceae-Caesalpinioideae) and African mahogany (Khaya spp., Meliaceae).

A weakly positive reaction (ring of froth) is produced by beech (Fagus sylvatica, Fagaceae).

For more information, see Dyer (1988), Quirk (1983), Cassens & Miller (1981).

#68. Splinter burns <"burning splinter test">/

1. to full ash/

2. to partial ash/

3. to charcoal/

— Full or complete ash = ash more or less retaining the shape of the original splinter.

Partial ash = ash that shrinks in size in comparison to the original splinter, has a tendency to drift away, and usually feels gritty when rubbed between the fingers.

Charcoal = the blackened and charred remains of a splinter, which usually burned slowly and/or with difficulty, or the black and charred remnant of the splinter with a fine thread of black or grey ash which may remain attached.

PROCEDURE

Prepare match-sized (approximately 2 x 2 x 50 mm) splinters from sound outer heartwood, insure the wood is at least air-dry. The splinter must be ignited with a match, and devices (e.g., lighters) producing higher temperatures must be avoided. Ignite the splinter while it is held in a vertical position with a pair of tweezers/forceps. While the splinter is burning, hold it in a horizontal position and turn it slowly.

Some timbers will burn with relative ease, e.g., balsa (Ochroma pyramidale, Bombacaceae), while others may show considerable reluctance, e.g., afzelia (Afzelia spp., Fabaceae-Caesalpinioideae). If it appears that the flame will extinguish before the splinter has burned fully, combustion may be aided by gently returning the splinter to a vertical position and then back to horizontal.

After the flame has died, it is important to allow the glowing part of the splinter to extinguish before placing the remnant on a cold surface.

COMMENTS

Certain timbers may crackle or produce bright sparks, e.g., limba (Terminalia superba, Combretaceae), while others may produce a characteristic black smoke, e.g., ramin (Gonystylus spp., Gonystylaceae), or exude coloured compounds while they burn. All these features may be recorded in a description.

The descriptive classifications for appearance of the burnt splinter are those first recommended by DADSWELL & BURNELL (1932). Apart from its use in CSIRO keys, ANONYMUS (1960) has implemented the feature and suggested that it is of little value except in distinguishing between some timbers which are closely related anatomically.

For further information on the burning splinter test, which sofar has only been used on a very limited scale, see MANN (1921), WELCH (1922), SWAIN (1927), and MENNEGA (1948).

#69. Colour of ash <"burning splinter test">/

1. white to grey/

2. bright white/

3. yellow-brown/

4. <other than white, grey, yellow or brown; specify>/

COMMENT

In some English-language literature, 'buff' is used to describe splinters that have the colour of pale tanned leather, a yellowish-brown (state 3).

#70. <Physical and chemical tests, additional observations or comments:>/

Additional information

#71. <Timber specific standards and information brochures:>/

COMMENT

This character serves for listing additional reading for the respective timber in the database, for instance technical information leaflets or relevant CITES treatises, which can be consulted for further information.

#72. <File names:>/

#73. <Illustrations:>/


The interactive key allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, and geographical distribution.

Cite this publication as: ‘Richter, H.G., Gembruch, K., and Koch, G. 2014 onwards. CITESwoodID: descriptions, illustrations, identification, and information retrieval. In English, French, German, and Spanish. Version: 16th May 2014. delta-intkey.com’.

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